Electric clock self-starter



July 25, 1967 J. L. KLINCK ETAL 3,332,229

ELECTRIC CLOCK SELF- STARTER Filed May 11, 1964 2 Sheets-Sheet 1 INVENTORS JOHN L. KLINCK JOHN A VAN HORN RICHARD T. CAMPBELL zg m m) A,

ATTORNEY July 25, 1967 J. 1.. KLINCK ETAL 3,332,229

ELECTRIC CLOCK SELF- STARTER Filed May 11, 1964 2 Sheets-Sheet 2 48 INVENTORS JOHN L. KLINCK JOHN A. VAN HORN RICHARD T. CAMPBELL ATTORNEYfi United States Patent 3,332,229 ELECTRIC CLOCK SELF-STARTER John L. Klinclr, John A. Van Horn, and Richard '1. Campbell, Lancaster, Pa., assignors to Hamilton Watch Company, Lancaster, Pa., a corporation of Pennsylvania Filed May 11, 1964, Ser. No. 366,289 13 Claims. (Cl. 5828) This invention relates to starters for oscillating devices and more particularly to an automatic and all electric self-starter for use in electric watches.

In assignees commercial electric watch, the balance wheel is impulsed by periodically completing a circuit from a small electrical battery to a pie or sector shaped coil carried by the balance wheel. This circuit is completed by the engagement of a pair of electrical contacts which are closed during only a small portion of the movement of the balance wheel for a complete cycle or oscillation. The closure of these contacts normally occurs near but not always at the rest position of the balance wheel. For this reason, it is not only possible, but quite likely that the watch can be stopped with the contacts open and the electrical circuit to the impulsing coil broken.

Various arrangements have been provided in the past for starting up an electric timepiece of this type that has been stopped with the contacts open. These include separate electromagnetic circuit arrangements having a spring finger or the like movable to engage and brush past the edge of the balance wheel to physically push the balance wheel into its first oscillation. Other self-starters have included a separate impulsing circuit, including multiple power supplies and a separate switching arrangement.

While some of these earlier arrangements have provided satisfactory self-starting, they do require fairly large and relatively expensive components, undesirable for use in a commercial electrical watch Where size is all important and where cost must be maintained as low as possible. The starter of the present invention is completely electrical in nature having no moving parts, is of relatively simplified construction in that it works off of the conventional power supply and requires only a single outside switch, is highly reliable in operation, may be incorporated in the small areas available in an electric watch, and does not unduly increase the watch expense.

In the present invention, when the outside switch is manually closed (assuming the watch contact points to be open) current flows through a second or starting circuit from the battery through the coil by way of a suitable capacitor so that the coil receives a starting impulse from the circuit bypassing the open watch contacts. This capacitor circuit impulse causes the balance wheel to begin oscillations, periodically closing the Watch internal contacts, so that the watch begins to be impulsed in the normal manner. After the first half oscillation, the capacitor is essentially charged and the starting circuit is effectively disabled. Provision is also made for discharging the capacitor when the outside switch is opened and the power removed, so that by the time oscillations of the watch have stopped, the capacitor is completely discharged and ready to again perform its starting function.

It is therefore one object of the present invention to provide a novel starter for oscillating systems.

Another object of the present invention is to provide a self-starter for watches and clocks.

Another object of the present invention is to provide an all electric automatic self-starter particularly suited for use with electric watches.

Another object of the present invention is to provide a horological device incorporating an all electric selfstarter of simplified construction with no moving parts.

Patented July 25, 1967 Another object of the present invention is to provide an electric watch having a capacitive self-starting circuit.

Another object of the present invention is to provide an electric watch having an energizing or drive coil carried by the balance wheel, and a battery periodically coupled to the coil through a pair of contacts one of which moves in conjunction with oscillations of the balance wheel so that the watch is susceptible of being stopped with the circuit from the battery to the coil broken. A starter circuit including a series capacitor and rectifier diode and a resistor in shunt with the capacitor is connected from the battery to the coil, so that the coil may be energized through the capacitor to cause starting oscillations of the balance wheel. Upon charging up of the capacitor from the battery, the starting circuit is effectively disabled and the watch runs in the normal manner.

These and further objects and advantages of the invention will be more apparent upon reference to the following specification, claims and appended drawings, wherein:

FIGURE 1 is a schematic diagram of a portion of a watch constructed in accordance with the present invention incorporating the novel starting circuit of this invention;

FIGURE 2 is a partially schematic elevational view showing the manner of electrically connecting the starting circuit to the watch coil of FIGURE 1;

FIGURE 3 is a schematic diagram similar to FIGURE 1 showing a modified embodiment of the present invention eliminating the necessity for a separate flexible lead; and

FIGURE 4 is a partially schematic elevational view showing an electric watch incorporating the modified embodiment of the starting circuit of FIGURE 3.

Referring to the drawings, there is shown in FIGURE 1 a portion of an electric watch 10 including an energizing coil 12 of generally pie or sector shape forming a portion of the drive circuit of the electric watch. Assignees commercial electric watch utilizes such a coil which is mounted on a balance Wheel 44 in FIGURE 2 to oscillate therewith in the manner disclosed in assignees US. patent, 3,015,206 or more recently in assignees copending application, Ser. No. 147,616 filed Oct. 25, 1961. Coil 12 is carried by balance wheel 44 in turn mounted on a balance staif 46 connected to one end of a conventional hairspring illustrated diagrammatically at 14 in FIGURE 1. The other side of the hairspring is grounded at 16, usually to the pillar plate of the watch forming the electrical ground for the positive side of the watch battery.

As further illustrated in FIGURE 1, a one and onehalf volt battery 18 has its positive terminal 20 connected to a ground as at 22 (i.e., to the pillar plate), and its negative terminal 24 is connected to a contact of an outside switch 26. This switch is manually operated by the wearer of the watch to stop and start the watch as desired. For example, the switch 26 may be actuated by axial movement of the setting stern of a watch in a well known manner.

Coil 12 is provided with a bracket screw 28 usually made of gold so as to be electrically conductive and this screw is coupled by lead 30 and contact points 31 and 33 forming internal switch 32 to the other contact of the outside switch 26. Screw 28 is electrically connected to its bracket which is in turn connected to the other end of the coil 12, i.e., the end of the coil remote from the hairspring 14. Contact points 31 and 33, of course, represent the internal contacts of the watch, and may include a movable contact 31 carried by, but insulated from, a roller 45 mounted on the balance staff 46. A spring arm as in Patent 3,015,206 or a combination contact-index wheel may form the yieldable contact 33. During oscillations of the balance wheel, the two contacts momentarily come together to complete a circuit from positive terminal 28 of the battery through ground, balance cock 52 and stud 54, through hairspring 14, collet 56, balance staff 46 and balance wheel 44, through coil 12 and by way of lead 30, switch 32, and switch 26 to the other or negative side of the battery 24. This periodic closure of the contact points 31 and 33 serves to supply energizing current impulses to the coil which interact with a magnetic field generated by cylindrical permanent magnets such as 42 positioned adjacent the path of movement of the coil so as to impart periodic thrusts to the balance wheel, resisted in a well known manner by the hairspring 14.

In the present invention one side of the coil 12, i.e., the side remote from hairspring 14, is also connected to an automatic self-starting circuit. This is accomplished in FIGURE 1 by connecting coil bracket screw 28 by way of a flexible lead 34, rectifier diode 36 and capacitor 38 to the other side of switch 32 so that these elements in series bypass or shunt the internal switch 32 formed by the contact points 31 and 33. A relatively large resistor 40 is in turn shunted across capacitor 38.

In operation assuming that the watch has stopped with the contact points 31 and 33 open, if switch 26 is closed a circuit will be completed by way of ground through the coil 12 by way of lead 34, diode 36 and capacitor 38. Since the voltage across a capacitor cannot change instantaneously the capacitor acts as a short circuit for the leading edge of the impulse from battery 24 and this impulse acts to supply a starting pulse or kick to the coil which causes the balance Wheel to begin oscillation since the resulting current impulse through the coil creates a magnetic field which interacts with the magnetic field from the permanent magnets adjacent the coil to impulse the wheel. While it is quite difficult to assure that the watch will always stop with the contacts closed, it is an easy matter to adjust the hairspring and balance assembly such that the rest position of the balance wheel will be sufficiently consistent so as to always bring it under the influence of the field from one of the permanent magnets 42 to initiate oscillations of the balance.

FIGURE 2 illustrates the manner of establishing the electric circuit and illustrates the balance wheel 44 carried by rotatable balance staff 46 in a conventional manner. The lower end of the balance staff is journaled in suitable jewel bearings provided in grounded pillar plate 48 While the upper end of the balance staff is similarly rotatably received in jewel bearings in the arm 50 of a stationary balance cock 52 mounted on the pillar plate 48. Arm 50 also secures a stud 54 attached to the outer end of the hairspring 14. The inner end of the hair spring is attached to a collet 56 rigidly secured to and rotatable with the balance staff 46.

Insulated flexible lead 34 is connected to the gold bracket screw 28 and passes through a suitable insulated hole in the collet 56 and a similar hole 58 in arm 50 and is carried out above the balance cock to the diode 36. Hole 58 in arm 50 of the balance cock, as well as the corresponding hole in collet 56, may have its edges coated with a suitable insulating plastic and flexible lead 34 is likewise preferably provided with an insulated sheath to prevent inadvertent contact with any of the metallic elements such as the balance staff or balance cock. Flexible lead 34 is provided with a plurality of loops 60 to accommodate the relative movement between the oscillating collet 56 and the stationary balance cock 52. It is apparent that the loops 60 may take the form of an auxiliary hairspring insulated from the staff 46, and the hole 58 replaced by a stud insulated from the arm 50 to which lead 34 is attached.

FIGURE 3 is a schematic diagram similar to that of FIGURE 1 of a modified system with like parts bearing like reference numerals. The system of FIGURE 3 has the advantage that it eliminates the necessity for the separate flexible lead 34 with the loops 60 or the auxiliary hairspring mentioned above.

In FIGURE 3 the coil 12 is illustrated as adhesively secured to the outer ends of a pair of bars 62 and 64 forming in conjunction with the cross arm 66 and enlarged hub portion 68 a part of the balance wheel. Affixed to the gold screw 28 is a wire '70 having its other end connected to the collet 56. The collet is in this embodiment provided around its interior with a layer of adhesive insulation 72, so that while it is physically carried by and rotatable with the balance staff 46, it is electrically insulated therefrom. The collet 56, is of course as before, connected to the inner end of the hairspring 14, the outer end of which is connected to a conductive stud 74 passing through the arm 50 of the balancecock 52 and insulated therefrom by a similar layer of plastic 76. A wire 78 completes the connection from the gold screw to the diode 36.

As illustrated in FIGURE 4, the ends of the balance staff 46 are rotatably received in bearings 80 and 82 one or both of which may be metal. The end of the coil electrically remote from the screw 28 is electrically connected to one of the arms 62 or 64 of the balance wheel and is electrically connected by way of cross arm 66 and hub 68 to the balance staff 46. The balance staff is in turn connected at one or both ends through the metal bearings to the grounded pillar plate either directly at the lower end of the balance staff or by Way of the balance cock 52 from the upper end of the balance staff. This connection is represented in FIGURE 3 by the ground connection at 84.

The operation of the embodiment of FIGURES 3 and 4is similar to the embodiment of FIGURES 1 and 2, as described above. With the switch 32 open as indicated by the spacing between the contact 86 on roller 88 and the toothed combination contact-index wheel 90 in FIG- URE 4, electric current flows from the battery 18 via the ground path through the pillar plate 48, either of metallic bearings 80, 82 or both, the balance stag or arbor 46, balance wheel 44, and the coil 12 to the coil bracket screw 28. The electric current flow continues from the screw 28 through the wire 70, the hairspring 14, and the conductive stud 74 to diode 36, capacitor 38 and thence to the negative side of the battery com leting the circuit. In this construction the conventional hairspring regulator 92 is provided with a layer of insulation 94 to insulate it from the remainder of the watch, so that the current flow is not shorted.

In operation, with the index wheel 90 removed (so that switch 32 is always open) and outside switch 26 closed, the electrical circuit is completed through capacitor 38 and the balance unit commences to rotate. After a few oscillations it slows down and comes to rest as the capacitor is charged. The size of capacitor 38 affects not only the number of oscillations of the balance unit, but also the rate at which the balance unit slows down and comes to rest. With resistor 40 relatively large, capacitor 38 charges to the potential of the battery and the battery drain through the resistor is negligible.

When the index wheel 90 is put in place and the outside switch 26 again closed, the balance unit commences to oscillate due to the influence of the self-start circuit. The contact points then close periodically and normal operation of the balance unit ensues as the self-start current dles toward zero. Diode 36 is used in the self-start circuit to avoid capacitor discharge. Resistor 48 discharges the capacitor 38 when the outside switch 26 is open, since during normal operation the capacitor 38 remains charged. When the external switch is opened the balance dies down and by the time it comes to rest, the resistor has discharged the capacitor so that the watch is immediately capable of again electrically self-starting.

While both embodiments have been described in conjunction with open switch 32 it is understood that the starting circuit has no adverse effect if the watch stops with contacts 31 and 33 engaged so that switch 32 is closed. Should this happen in either embodiment start up is normal and is influenced by both circuits.

It is apparent from the above that the present invention provides a novel self-starting unit for horological devices such as watches and clocks and one that is particularly suited for use with assignees commercial electric watch. The important features of the present invention over prior constructions include the simplier, less expensive, more reliable mechanical construction, including the necessity for only one power source and one outside switch. The elements are all of small size and light weight making them particularly suited for use in the small space available in an electric watch. None of the component values are critical, but in one embodiment constructed in accordance with the present invention, and useable in the arrangement of either FIGURES 1 and 2 or in FIGURES 3 and 4, capacitor 38 had a value of 22 microfarads and resistor 40 was a 0.68 megohm resistor.

We claim:

1. An electric watch comprising a battery having one terminal grounded to the pillar plate of said watch, an oscillating balance system, a drive coil for electromag netically energizing said balance system, an internal switch connected in series with said drive coil between the other terminal of said battery and ground, said switch having a portion thereof movable with said balance system and being periodically closable whereby said balance system may come to rest with said internal switch open, an outside switch in series with said internal switch, and a capacitor shunting said internal switch.

2. A watch according to claim 1 wherein said balance system includes a balance wheel, and said drive coil is carried for movement with said balance wheel.

3. A watch according to claim 2 including a diode in series with said capacitor across said internal switch, and means for discharging said capacitor when said outside switch is opened.

4. An electric Watch comprising a balance staff, a balance wheel mounted for oscillation on said balance staff, a hairspring coupled to said balance stafl? for supporting oscillations of said balance wheel, a drive coil carried by said balance wheel, at least one permanent magnet adjacent the path of movement of said drive coil, a battery, an internal switch electrically connecting said battery to said drive coil, said internal switch comprising a pair of contacts, one of said contacts being yieldable while the other is mounted for oscillation with said balance staff whereby said contacts periodically close with movement of said balance staff, and a starting circuit coupling said battery to said drive coil and bypassing said internal switch whereby said starting circuit impulses said drive coil to start oscillations even when said internal switch is open.

5. A watch according to claim 4 wherein said starting circuit comprises means for effectively disabling itself after the initial oscillations of said balance wheel.

6. A watch according to claim 5 wherein said disabling means comprises a capacitor adapted tobe charged to the potential of said battery.

7. A watch comprising a grounded pillar plate and a balance cook, a balance staff having one end journaled in said pillar plate and its other end journaled in said balance cock, a balance wheel on said balance staff. a hairspring engaging said balance staff for supporting oscillations of said balance wheel, a pie-shaped drive coil carried by said balance wheel, one end of said coil being electrically connected to said balance Wheel, at least one permanent magnet positioned adjacent the path of movement of said drive coil whereby the fields from said coil and magnet interact to impart a thrust to said coil and balance wheel, means electrically coupling said balance staff to said pillar plate, a battery, means coupling one side of said battery to said pillar plate, a roller on said balance stair, an insulated contact carried by said roller, means electrically coupling said insulated contact to the other end of said drive coil, a yieldable contact engagea-ble by said insulated contact during oscillation of said balance wheel to complete a circuit from said other end of said drive coil to the other side of said battery, and a starting circuit including a capacitor bypassing said contacts and coupling said other end of said drive coil to said other side of said battery.

8. A watch according to claim 7 wherein said capacitor is in series with a diode which prevents discharge of said capacitor through said drive coil, and a relatively large resistor shunting said capacitor.

9. A watch according to claim 8 wherein said balance staff is coupled to said pillar plate through said hairspring, and means including a flexible lead coupling said other end of said drive coil to said capacitor.

10. A watch according to claim 8 wherein said balance staff is coupled to said pillar plate by at least one metal bearing, and means including said hairspring for coupling said other end of said drive coil to said capacitor.

11. A watch according to claim 10 wherein said yieldable contact comprises a toothed con-tact wheel.

12. A timepiece comprising a battery, a balance system, a drive coil for energizing said balance system having one terminal coupled to one terminal of said battery, a switch coupling the other terminal of said battery to the other terminal of said drive coil, one contact of said switch being movable with said balance system, a capacitor coupled across said switch, and a rectifier diode in series with said capacitor.

13. A timepiece comprising a battery, a balance system, a drive coil for energizing said balance system having one terminal coupled to one terminal of said battery, a switch coupling the other terminal of said battery to the other terminal of said drive coil, one contact of said switch being movable with said balance system, a capacitor coupled across said switch, and a discharge resistor across said capacitor.

References Cited UNITED STATES PATENTS 2,084,657 6/1937 Sears 310 39 X 2,711,501 6/1955 Contant 310 39 X 2,945,168 7/1960 Steinke 31s-12s 3,124,731 3/1964 Eysen et al 310-36 X 3,140,376 7/1964 Tilse et al. 310-39 X 3,156,857 11/1964 Herr et a1. 318132 MILTON O. HIRSHFIELD, Primary Examiner. D. F. DUGGAN, Assistant Examiner. 

7. A WATCH COMPRISING A GROUNDED PILLAR PLATE AND A BALANCE COCK, A BALANCE STAFF HAVING ONE END JOURNALED IN SAID PILLAR PLATE AND ITS OTHER END JOURNALED IN SAID BALANCE COCK, A BALANCE WHEEL ON SAID BALANCE STAFF. A HAIRSPRING ENGAGING SAID BALANCE STAFF FOR SUPPORTINF OSCILLATIONS OF SAID BALANCE WHEEL, A PIE-SHAPED DRIVE COIL CARRIED BY SAID BALANCE WHEEL, ONE END OF SAID COIL BEING ELECTRICALLY CONNECTED TO SAID BALANCE WHEEL, AT LEAST ONE PERMANENT MAGNET POSITIONED ADJACENT THE PATH OF MOVEMENT OF SAID DRIVE COIL WHEREBY THE FIELDS FROM SAID COIL AND MAGNET INTERACT TO IMPART A THRUST TO SAID COIL AND BALANCE WHEEL, MEANS ELECTRICALLY COUPLING SAID BALANCE STAFF TO SAID PILLAR PLATE, A BATTERY, MEANS COUPLING ONE SIDE OF SAID BATTERY TO SAID PILLAR PLATE, A ROLLER ON SAID BALANCE STAFF, AN INSULATED CONTACT CARRIED BY SAID ROLLER, MEANS ELECTRICALLY COUPLING SAID INSULATED CONTACT TO THE OTHER END OF SAID DRIVE COIL, A YIELDABLE CONTACT ENGAGEABLE BY SAID INSULATED CONTACT DURING OSCILLATION OF SAID BALANCE WHEEL TO COMPLETE A CIRCUIT FROM SAID OTHER END OF SAID DRIVE COIL TO THE OTHER SIDE OF SAID BATTERY, AND A STARTING CIRCUIT INCLUDING A CAPACITOR BYPASSING SAID CONTACTS AND COUPLING SAID OTHER END OF SAID DRIVE COIL TO SAID OTHER SIDE OF SAID BATTERY. 